[Federal Register Volume 59, Number 242 (Monday, December 19, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30537]
[[Page Unknown]]
[Federal Register: December 19, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 93-ANE-43; Amendment 39-9093; AD 94-25-09]
Airworthiness Directives; Rolls-Royce, plc Spey Series Turbofan
Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to Rolls-Royce, plc Spey series turbofan engines, that
requires a one-time inspection of stage 1 and stage 2 high pressure
turbine (HPT) and low pressure turbine (LPT) disks for cracks and
corrosion pitting. This amendment is prompted by a report of a stage 7
high pressure compressor disk found cracked due to corrosion. The
actions specified by this AD are intended to prevent an HPT or LPT disk
burst due to cracking attributed to corrosion, which may result in an
uncontained engine failure.
DATES: Effective February 17, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 17, 1995.
ADDRESSES: The service information referenced in this AD may be
obtained from Service Manager, Spey engines, Rolls-Royce, plc, East
Kilbride, Glasgow G74 4PY, Scotland. This information may be examined
at the Federal Aviation Administration (FAA), New England Region,
Office of the Assistant Chief Counsel, 12 New England Executive Park,
Burlington, MA; or at the Office of the Federal Register, 800 North
Capitol Street, NW., Suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: John Fisher, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (617)
238-7149, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to Rolls-Royce, plc (R-R) Spey series
turbofan engines was published in the Federal Register on January 11,
1994 (59 FR 1500). That action proposed to require a one-time
inspection of stage 1 and stage 2 high pressure turbine (HPT) and low
pressure turbine (LPT) disks for cracks and corrosion pitting once the
disks have completed at least 40% of their published Group ``A'' cyclic
life limits as specified in the applicable overhaul manual. These disks
must be inspected in accordance with the applicable overhaul manual
during the engine's next shop visit where either the HPT or LPT disks
are removed after the effective date of this AD. Accomplishment of this
inspection will allow stage 1 and stage 2 HPT and LPT disks to complete
the remainder of their current published cyclic life limits. The
actions would be required to be accomplished in accordance with R-R
Service Bulletin No. Sp72-1044, dated September 1992.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the one comment received.
The commenter concurs with the AD as proposed.
In addition, the definition of shop visit has been clarified to
eliminate the reference to next scheduled disk inspection and include
next disk removal.
After careful review of the available data, including the comment
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes described
previously. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
The FAA estimates that 173 engines installed on aircraft of U.S.
registry will be affected by this AD and that the average labor rate is
$55 per work hour. The FAA estimates that it will take no additional
work hours per engine to accomplish the required actions to the HPT's
as the inspection is performed during regular turbine overhauls.
Approximately 80% of the engines will require an additional 25 work
hours of extra access, inspection, and rebuild time to perform the
required LPT inspection. Based on these figures, the total cost impact
of the AD on U.S. operators is estimated to be $189,750.
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a
significant economic impact, positive or negative, on a substantial
number of small entities under the criteria of the Regulatory
Flexibility Act. A final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
94-25-09 Rolls-Royce, plc: Amendment 39-9093. Docket 93-ANE-43.
Applicability: Rolls-Royce, plc (R-R) Spey 506-14 series, 511-14
series, and 555-15 series turbofan engines, installed on but not
limited to British Aerospace BAC 1-11 series and Fokker F28 series
aircraft.
Compliance: Required as indicated, unless accomplished
previously.
To prevent a high pressure turbine (HPT) or low pressure turbine
(LPT) disk burst due to cracking attributed to corrosion, which may
result in an uncontained engine failure, accomplish the following:
(a) Perform a one-time inspection for cracks and corrosion
pitting in stage 1 and stage 2 HPT disks that on the effective date
of this airworthiness directive (AD) have completed 40% or more of
their published Group ``A'' lives, in accordance with the procedures
and schedule described in R-R Service Bulletin (SB) No. Sp72-1044,
dated September 1992, at the next shop visit after the effective
date of this AD.
(b) Perform a one-time inspection for cracks and corrosion
pitting in stage 1 and stage 2 HPT disks that on the effective date
of this AD have completed less than 40% of their published Group
``A'' lives, in accordance with the procedures and schedule
described in R-R SB No. Sp72-1044, dated September 1992, at the
first shop visit after completing 40% of their published Group ``A''
lives.
(c) Perform a one-time inspection for cracks and corrosion
pitting in stage 1 and stage 2 LPT disks that on the effective date
of this AD have completed 40% or more of their published Group ``A''
lives, in accordance with the procedures and schedule described in
R-R SB No. Sp72-1044, dated September 1992, at the next shop visit
after the effective date of this AD.
(d) Perform a one-time inspection for cracks and corrosion
pitting in stage 1 and stage 2 LPT disks that on the effective date
of this AD have completed less than 40% of their published Group
``A'' lives, in accordance with the procedures and schedule
described in R-R SB No. Sp72-1044, dated September 1992, at the
first shop visit after completing 40% of their published Group ``A''
lives.
(e) Replace with a serviceable part, disks that do not meet the
inspection requirements described in section 72-50 of the applicable
R-R Spey Engine Overhaul Manual, prior to return to service.
(f) Mark disks that meet the inspection requirements described
in section 72-50 of the applicable R-R Spey Engine Overhaul Manual
in accordance with R-R SB No. Sp72-1044, dated September 1992, prior
to return to service.
(g) For the purpose of this AD, a shop visit is defined as an
engine removal where engine maintenance entails removal of either
HPT or LPT disks.
(h) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Engine Certification Office. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(i) Special flight permits may be issued in accordance with
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR
21.197 and 21.199) to operate the aircraft to a location where the
requirements of this AD can be accomplished.
(j) The inspection, and replacement, if necessary, of the disks,
shall be done in accordance with the following service bulletin:
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Document No. Pages Date
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R-R SB No. Sp72-1044...................... 1-2 September 1992.
Total pages........................... 2
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This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Service Manager, Spey engines,
Rolls-Royce, plc, East Kilbride, Glasgow G74 4PY, Scotland. Copies
may be inspected at the FAA, New England Region, Office of the
Assistant Chief Counsel, 12 New England Executive Park, Burlington,
MA; or at the Office of the Federal Register, 800 North Capitol
Street NW., suite 700, Washington, DC.
(k) This amendment becomes effective on February 17, 1995.
Issued in Burlington, Massachusetts, on December 2, 1994.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 94-30537 Filed 12-16-94; 8:45 am]
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